1. Field of the Invention
This invention relates to an electric circuit device which is formed by electrically connecting electric circuit components via electric connecting members.
2. Related Background Art
Heretofore, as techniques for electrically connecting electric circuit components, there have been known, for example,
1) wire bonding method PA1 2) TAB (Tape Automated Bonding) method (refer to, for example, Japanese Patent Public Disclosure (Kokai) No. 59-139636 (1984)) PA1 3) CCB (Controlled Collapse Bonding) method (refer to, for example, Japanese Patent Publication No. 42-2096 (1967), and Japanese Patent Public Disclosure (Kokai) No. 60-57944 (1985)) PA1 4) a method shown in FIGS. 1 and 2 PA1 5) a method shown in FIG. 3 PA1 6) a method shown in FIG. 4 and the like.
Method 4), as shown in FIGS. 1 and 2, is as follows.
That is, an insulating film 71 made of polyimide and the like is formed on portions other than a connecting region 5 of a first semiconductor device 4, a metal material 70 consisting of Au and the like is provided on the connecting region 5, and exposed surfaces 73 and 72 of the metal material 70 and insulating film 71 are then made flat. On the other hand, an insulating film 71' made of polyimide and the like is formed on portions other than a connecting region 5' of a second semiconductor device 4' , a metal material 70' consisting of Au and the like is provided on the connecting region 5' , and exposed surfaces 73' and 72' of the metal material 70' and insulating film 71' are then made flat.
Subsequently, the first semiconductor device 4 and the second semiconductor device 4' are then placed proximate to each other as shown in FIG. 2. After the placement, the connecting region 5 of the first semiconductor device 4 and the connecting region 5' of the second semiconductor device 4' are connected to each other via the metal materials 70 and 70' by performing thermocompression.
Method 5), as shown in FIG. 3 is as follows.
That is, an anisotropic conductive film 78 consisting of an insulating film 77 in which conductive particles 79 are dispersed is provided between a first circuit substrate 75 and a second circuit substrate 75'. After placing the first circuit substrate 75 and the second circuit substrate 75' near each other, a connecting region 76 of the first circuit substrate 75 and a connecting region 76' of the second circuit substrate 75' are connected to each other by pressurizing or pressurizing/heating.
Method 6), as shown in FIG. 4 is as follows.
That is, an elastic connector 83 consisting of an insulating material 81 in which metal wires 82 consisting of Fe, Cu and the like are disposed in a definite direction is provided between the first circuit substrate 75 and the second circuit substrate 75'. After placing the first circuit substrate 75 and the second circuit substrate 75' near each other, the connecting region 76 of the first circuit substrate 75 and the connecting region 76' of the second circuit substrate 75' are connected to each other by pressurizing.
Now, conventional bonding methods as described above have the following problems. That is, there exist restrictions in circuit design relative to bonding, a pitch size between adjacent conductors (a distance between centers of adjacent connecting regions) is large, a thinner device can not be realized, reliability is low due to corrosion or disconnection of conductors, deterioration in characteristics caused by the concentration of thermal stress between a bonding member and an electric circuit component and the like, it is difficult to replace only an electric circuit component when the electric circuit component fails, and the like.
In the technique shown in FIGS. 1 and 2, there are the following problems:
a) The exposed surface 72 of the insulating film 71 and the exposed surface 73 of the metal material 70, or the exposed surface 72' of the insulating film 71' and the exposed surface 73' of the metal material 70' must be made flat. Hence, production process for that purpose is increased, and production cost becomes high.
b) If there exists an unevenness between the exposed surface 72 of the insulating film 71 and the exposed surface 73 of the metal material 70, or between the exposed surface 72' of the insulating film 71' and the exposed surface 73' of the metal material 70' , the metal material 70 and the metal material 70' become disconnected to each other, and so reliability is decreased.
Furthermore, in the technique shown in FIG. 3, there are the following problems:
a) When connecting the connecting region 76 and the connecting region 76' by pressurizing after placing them near each other, it is difficult to apply a uniform pressure. Hence, there occur variations in connecting state, and as a result, variations in contact resistance value at the connecting regions become large. This fact causes a decrease in reliability of connection. In addition, since phenomena such as heating and the like occur when a large amount of current is passed, this method is unsuitable when it is intended to pass a large amount of current.
b) Even if a uniform pressure can be applied, variations in resistance value become large according to an arrangement of the conductive particles 79 in the anisotropic conductive film 78. Reliability in connection is thereby decreased. Furthermore, this method is unsuitable when it is intended to pass a large amount of current.
c) When a pitch between adjacent connecting regions (a distance between centers of adjacent connecting regions) is reduced, a resistance value between adjacent connecting regions becomes small. Hence, this method is unsuitable for a high-density connection.
d) Since resistance values change due to variations in the amount h.sub.1 of protrusion of the connecting regions 76 and 76' of the circuit substrates 75 and 75', it is necessary to exactly control the amount of variations of the h.sub.1.
e) When the anisotropic conductive film is used for the connection between a semiconductor device and a circuit substrate, and the connection between a first semiconductor device and a second semiconductor device, there exists the disadvantage that bumps must be provided on connecting regions of the semiconductor devices and so production cost becomes high.
Furthermore, when the technique shown in FIG. 4 is used for the connection between a semiconductor device and a circuit substrate, or the connection between a first semiconductor device and a second semiconductor device, there are the following problems:
a) It is necessary to apply a pressure, and so it is necessary to provide a pressurizing jig.
b) Since contact resistance between the metal wires 82 of the elastic connector 83 and the connecting region 76 of the first circuit substrate 75 or the connecting region 76' of the second circuit substrate 75' changes according to a pressurizing force and surface state, reliability in connection is small.
c) Since the metal wires 82 of the elastic connector 83 are rigid, the surfaces of the elastic connector 83, the first circuit substrate 75 and the second circuit substrate 75' have a large possibility of being damaged when a pressurizing force is large. On the contrary, reliability in connection becomes small when a pressurizing force is small.
d) Since the amount h.sub.2 of protrusion of the connecting regions 76 and 76' of the circuit substrates 75 and 75', the amount h.sub.3 of protrusion of the metal wires 82 of the elastic connector 83 and variations thereof influence variations in resistance value and damage, a contrivance for decreasing the variations is required.